Sampling apparatus



WORREL HERZ/G ATTORNEYS Oct. 15,'"1957 c. c. LAVAL, JR

SAMPLING APPARATUS Filed sept. 1:5. 1954 www nted States Thel present invention relates to earth sampling geological apparatus and more particularly to improvements in the coring tools therefor.

It is frequently important to make an analysis of subterranean soil and rock formations, for example, in the drilling for oil, gas, water and minerals and preparatory to setting of building and dam foundations. Apparatus for accomplishing such a result has long been known. In my copending U. S. applications S. N. 454,543, tiled September 7, 1954, and S. N. 455,620, led September 13, 1954, are shown improvements in such apparatus.

The improvements comprising the present invention pertain in particular to sampling apparatus employing explosive means for thrusting the sampling tools into earth penetrating engagement. Generally such apparatus provide an explosive charge which, when fired, drives the sampling or coring tool into the formation. Considerable thrust is obtainable by such explosive drive means and in this manner relatively hard formations can be penetrated. In the past however, greater emphasis has been placed on penetration than on convenient and dependable means for retrieving the tools and contained samples from the formations. As a result, sampling tools are often left irretrievably anchored in formations, are broken or damaged in attempts to pry them loose and after retraction frequently lose much or all of the collected sample.

Another problem encountered has been the inability to extend the sampling tool deeply into the formation penetrated. The sampling tools and associated apparatus of the general type under consideration are lowered within a bore hole and the sampling tools are adapted to extendl into the surrounding walls of the hole. Because of the size of the hole in relation to the apparatus, the size limitations of the tool, the hardness of the formation, the positioning of the apparatus and other factors, the penetrating depth of the tool has been limited to that closely adjacent to the bore hole wall. Particularly in iluidcontaining bore holes, the formation close to the bore hole wall is frequently contaminated and does not reflect accurately the true character of the formation. Much deeper penetration is clearly desirable.

Accordingly, an object of this invention is to provide improvements in sampling or coring tools adapted for deeper penetration into and more dependable retraction out of earth formations.

Another object is to facilitate the release of sampling tools driven into earth penetrating engagementv by explosive means. Another object is to provide a sampling apparatus utilizing explosive coring tool driven means with means for releasing exhaust gases during retraction of the tool from earth penetrating engagement.

Another object is to provide in a sampling apparatus adapted to thrust sampling tools into earth coring engagement by an explosive force, an arrangement for releasing gas pressures built up by the explosion automatically operable during retraction of the sampling tools.

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Another object is to provide the explosion chamber in a sampling apparatus having a sampling tool driven by explosive means with a gas exhaust port closed during extension of the tooland automatically opened during retraction of the tool.

Another object is to increase the penetrating depths obtainable by earth sampling tools.

Another object is to provide a sampling tool which substantially doubles in length in the extended position as compared to its retracted-position.

Another object is to provide a telescopic sampling tool.

Another object is to provide a telescopic sampling tool operable by explosive driving means and incorporating an arrangement for facilitating the release thereof from earth penetrating engagement, as set forth in several of j the preceding paragraphs.

Other objects are to provide improvements in sampling tools which enable more dependable action, import ad. ditional utility to the tool, are capable of simple and economical construction and are highly elfective for their intended purposes.

These and other objects will become more fully apparent upon reference to the following description.

In the drawings:

Fig. l is a longitudinal section through a'bore hole showing the sampling apparatus of the present invention supported therein.

Fig. 2 is a transverse section taken through the sampling apparatus of Fig.` 1.

Fig. 3 is a somewhat enlarged fragmentary longitudinal section through the sampling apparatus of Fig.Y 2`

showing the sampling tool in retracted position.

Fig. 4 is a view similarto Fig.3 but showing the` sampling tool in an outwardly extended position.

Fig. 5 is a fragmentary longitudinal section similar to Fig. 3 but showing another form of sampling tool of the present invention.

Referring more particularly to the drawings:

The sampling apparatus of the present invention, gen! erally denoted by the numeral 10 in Fig. l, is supported on a cable 11 for elevational positioning within a bore hole 12. The bore hole shown is filled with a fluid 13 representing water, oil or the like but it is to be understood that the samplingvapparatus of this invention can beutilized in inany other operational environmentsfor the purpose; of securing samples of the earth formation or other medium having a borehole or cavity therein requiring investigation.

Thesampling apparatus 10 includes an elongated housing 2t) of cylindrical or other convenient shape. The housing is hollow and a mounting body or block 21 is received within the housing in fixed support position therein. The mounting body provides a plurality of ramming chambers 22 which are transversely disposed and longitudinally spaced in the mounting body. The ramming charnbers are adapted to receive a plurality of sampling tools 23 for extension, as shown in Figs. 1, 24, and 4, and retraction relative to the housing, as shown in Fig. 3. p

The construction of the ramming chambers 22 and the sampling tools 23 therein are identical and for purposesof simplicity only one is described herein. Each of the ramming chambers 22 provides a closed end 30 and ani open end 31 opening lexteriorly of the housing 20. The

open end of the chamber is threaded and an annular nut 32 is threadably received in this end. The annular nut f has a central bore 33 therein which extends through the nut and is axially aligned with the chamber 22.

A ram 40 is mounted in the chamber 22 for slidable reciprocation between a retracted position within the body 21 and an extended position adjacent to the open end 31 ing an eccentric bore 42 extending therethrough and an ellipsoidal central depression 43 adapted to receive a shaped charge. A diametrically reduced body portion 44 extendsl from the piston head and is provided with a threaded boss 45 extended toward thel open end of the chamber. Although anA ellipsoidal depression is preferred, other shapes in the ram headcouldbe provided to accommodate a charge or, in fact, a flat ram head without a depression could be used.

The sampling to-ol 23 includes a cylindrical member 50 having an outer wall 51 and a core-receiving barrel or bore 52. The barrel is provided with a threaded end 53 which is tted on the threaded boss 45. The outer end ofv the cylindrical member on theI outer wall thereof is bevelled, as at 54, With the bevel sloping convergently relative to the barrel.

Because of its mounting on the ram 40, the sampling tool 23 is adapted for reciprocation. inA the chamber between a retracted position therein as seen. in Fig. 3, and

a position extended from the housing 20, as seen in FigsrZ and 4. A coil spring 60 is positioned inV the chamber around' thel cylindrical` member 50 of the sampling tool.

and the extended body 44' of the'ram and bears against the annular nut 32 and the piston head 41.. It is quite apparent that the spring is adapted to urge the ram and therefore the sampling. tool into retracted position.

Considering Fig. 3,. an explosive charge of tiring powder 65 is positioned in the chamber between the closed end thereof and the piston head- 41 oftheram. A portion of the powder iills the depression 43 of the piston head and a substantially frusto-conical nose 66 having a threaded fitting. 67 is received in fluid-tight relation in an opening 68 in the housing for extension into the depression 43. Suitable packing seals, not shown, may be employed to insure a Huid-tight connection of the fitting in the opening. This construction is conventional in detonators and briefly, is used to form .and direct properly the force of the explosion. An igniting means 69 conveniently providing a spark gap is mounted in the body 21, being embedded within the explosive charge. Control wires 70 are connected to the iiring means and extend through the mounting body 21l upwardly'into the upper portion of the housingv 20.

The housing 20 provides an exhaust vent 75 which permits communication between the chamber 22 and the exterior of the housing. A ball check valve 76 including a threaded plug 77 is positioned in the exhaust vent and, as will be apparent from Figs. 3 and 4, permits unidirectional gaseous or fluid ow from the ramming chamber to the exterior of the housing. The plug 77 is provided with. a bore 78 to permit the passage of gases or fluids through the plug when the Valve is opened.

An elongated pin 85 is arranged in the chamber 22 extended through the eccentric bore 42 between the closed end of the chamber and the annular nut 32. The eccentric bore and the diameter of the pin are designed to provide a sloppy slidable fit for the pin in the bore, as will be apparent from an observation of Figs. 3 and 4. Thus, appreciable lateral movement is permitted the pin Within the eccentric bore. A collar 86 is provided on that portion of the pin which is adjacent to the annular nut. A spring 87 bears against the collar 86 encompassing the pin 85 and being connected at its other end to the annular nut.

When the ram 40 is in retracted position, the spring 87 is adapted to maintain the pin 85 in aligned plugging relation in the exhaust vent 75 as seen in Fig. 3; The spring is adapted to hold the pin in this plugging position during substantially the full extension stroke of the ram 40. When the ram is in substantially fully extended position, as is illustrated in Fig. 4, the'piston head 41 abuts the collar 86 and urges the spring 87 into compressed condition. Because of. the sloppy fit ofthe pin in the eccentric bore 42, the' pin is. removed from the exhaust vent'- and drops downwardly therefrom. Again, because of said sloppy it and due to the urging of spring 87 against the collar 86, the pin is maintained in misaligned downward position relative to the exhaust vent during substantially the full retraction of the ram. It will be quite apparent that as the ram approaches its fully retracted position the pin will be gradually urged into plugging position within the exhaust vent thus being reset for a further cycle of operation. If desired, the pin may be manually inserted in the vent but as explained, during normal operation the pin is replaced automatically.

Another exhaust valve is provided in the housing 20 and the mounting body 21 permitting communication between the ramming chamber 22 and the exterior of the housing. A ball check valve 96 having a threaded plug 97 is fitted in the exhaust valve 95 and a bore 98 is provided in the plug, as before. The ball check valve permits unidirectional gaseous uid communication from the ramming chamber to the exterior of the housing. However, the passage-95 is so positioned that it does not communicate with the ramming chamber until the ram is in its substantially fully extended position, as seen in Fig. 4. The incorporation of passage 95 is desirable in that it aids in cleaning out excess gases from the chamber but its presence is not essential to the proper operation of the operation.v

The housing 20 is provided in its upper portion above the mounting body 21- with acontrol mechanism, generally indicated by thenumeral N5. Individual wires 70 are provided between the control mechanism and each of the ignitor-s 69 associated with the sampling tools 23. A single control wireV 106 extends from the control mechanism upwardly through the housing and along with the cable 11 to a control station, not shown, at the surface of the hole.V The control mechanism is adapted to permit the individual firing, that is extension and retraction, of the sampling tools. Briefly, in response to closing of a control switch, not shown, connected to wire 105, this mechanism is adapted to iire one of the sampling tools whereupon a stepped switch in mechanism is automatically thrown to a second position for preconditioning a second one of the sampling tools for firing. Upon a subsequent closing. of the control switch, said second sampling tool is` lired and a third tool preconditioned. The other sampling tools are likewise operated by stepped progression of' a switch in the control mechanism successively preconditioning and tiring each. of the sampling tools for extension and retraction. In this manner, samples of earth formation can. be. taken at a variety of selected levels.

Operation The operation of this invention is believed to be readily apparent and is brieily summarized at this point. With all of the* sampling tools 23 all in a retracted position within the housing 20, theV pins 85 plugging their respective exhaust portsV 75, and a charge 65 packed in the chamber 22, as seen inY Fig. 3, the sampling apparatus is lowered in the bore hole 12 and the uppermost sampling tool 23 is positioned adjacent to an'area wherein it is desired to obtain an earth sample.

A switch, not shown, connected to wire 106 at the surface ofthe well is closed thereby forming a series circuit between' a'V suitable source of voltage, not shown, the con trol mechanism 105 and the ignitor firing means 69 embedded in the explosive charge 65 associated with the upper samplingv tool. When the charge is tired the ram 40 is thrust under considerable pressure into its extended position. within the chamber 22 and the sampling tool 23 is likewise thrust into its position of outward extension relative to the housing 2i). The force placed behind the sampling toolV drives it into the walls of the bore hole adjacent thereto. The bevels 54 on the outer wall 51 of the sampling tool permit forceable entry of the tool into the soil orV formation.y It should be noted that these bevels are placed on the outer wallrather than on the interior of the barrel 52].v Thus, their wedging eiiect is retained while eliminating the possibility of jamming' or plugging theentrance to the barrel which would be possible with bevels arranged in outwardly diverging position on the interior of the cylindrical member 50. In this manner, the barrel 52 receives a sample of the earth formation therein.

`As soon as the ram 40 is forced into its substantially fully extended position the piston head 41 abuts against the collar 86 on pin 35 and pulls the pin out of plugging relation from the exhaust vent 75. It will be 4noted that during the expansion stroke of the ram, the pin 85 precludes the opening of the exhaust vent 75. Obviously, this is the result desired inasmuch as it is necessary t-o conne all of the pressure produced by the explosive charge within the chamber 22 and behind the piston head 41. However, when the ram has reached its extended position, it then becomes desirable to release any excess exhaust or gaseous pressures remaining in the chamber 22 behind the piston head. The excess of pressure beyond that needed to drive the tool into the formation is relieved through port 95 which is adapted to open under pressure in the fully extended position of the tool. This relief of pressure also minimizes recoil on the housing.

It is also necessary to relieve the pressure behind piston head 41 to enable retraction of the tool. As the ram 46 is urged toward retracted position by spring 60, the piston head forces the exhaust gases within the chamber 22 to open valve 76 so that the gases are expelled from the chamber. Further, the sloppy t of pin 85 in bore 42 permits the pin to rest on the tiring nose 66 and thus the exhaust passage 75 is conditioned for opening during sub-A stantially the full retracted stroke. As the ram 40 approaches substantially the fully retracted position, the pin is brought again into plugging alignment in the passage 7 5.

This completes one cycle of operation and the apparatus is ready for repositioning in the bore hole to obtain a sample at a different elevation. The control mechanism 105 has conditioned the firing mechanism associated with the center sampling tool, or any of the other empty tools mounted in the housing, for firing and thus this tool is aligned opposite the desired position in the bore hole. The control switch at the remote control station is thrown and the tool is extended and retracted in the same manner as the uppermost tool, above described. Depending upon the number of sampling tools 23 and the number of samples which it is desired to obtain, the above sequence of steps is repeated until one or more of the sampling tools has an earth sample packed in its barrel 52 and all of the sampling tools are in their retracted positions within the housing. At this point, the housing 20 is'lifted in the well by cable 11 and brought to the surface thereof.

The annular nuts 32 are rst removed thereby permitting access to the cylindrical member Si) of the sampling tools 23. The cylindrical members are unthreaded from their rams 40 and the sample pried, jarred or otherwise dislodged from their barrels 52 for inspection or laboratory analysis.

The cylindrical members 50 are then replaced on their rams and the annular nuts 32 again threaded tightly in place. The fittings 6'7 and noses 66 are removed and a new charge `65 packed in each chamber 22. At this time, it is advisable to check to see if pin 85 is properly tted in vent 75. The fittings and noses are replaced, the central mechanism 105 reset and the apparatus is ready for further use.

Second form Referring to Fig. 5, a housing 120 providing a mounting body 121 is shown. As before, the body provides a chamber 122 having an outer end wherein is received an annular nut 124' having a concentric bore 125. The sampling tool, generallyfindicatedat 130, is a telescopic arrangement providing an outer member 131 and an inner member 132 adapted for telescopic movement relativeto each other. The outer member has a piston head 133 with a concentric truste-conical bore134. A substantially cylindrical outer member 135 extends from the piston head and is slidably received within the bore of the annular nut. The -outer member provides an inner chamber 136 which receives at its open end 'an annular nut 137 concentric with .the annular nut 124 and providing a concentric bore 138. A coil spring 139 encompasses the outer member 135 being positioned between the annular nut 124 and the piston head for urging the outer member into a retracted position.

The inner member 132 likewise provides a piston head 140 and an inner cylinder 141 extended therefrom both of which are received within the inner chamber 136 of the outer member, the inner cylinder 141 being slidably extensible and retractable within bore 138 of nut 137. The inner cylinder has a core-receiving barrel 142 opening outwardly of the housing provided with a bevelled mouth. A coil spring 143 surrounds the inner cylinder bearing between the annular nut 137 and the piston head 140 for urging the inner member into retracted position within the outer member and with the piston head 140 bearing 1against the piston head 133 in closed relation to one end of frusto-conical bore 134.

When the sampling tool 130 is in its retracted position, an explosive charge 150 ills the space between the lpiston head 133 and the closed end of chamber 122. The explosive charge also fills the frusto-conical bore 134 in the piston head 133, being packed against the piston head 140. A frusto-conical nose 151 providing a fitting 152 is threadably received in the housing 120, being embedded in the explosive charge 150. A suitable tiring means or ignitor, shown as a spark gap 153, is also embedded in the explosive charge. A control wire 154 is connected to the tiring means and extends upwardly through the body 121 to an upper position in the housing 120 for connection to a control mechanism in the same manner as above described in relation to the -form of Figs. 2 to 4.

This form of sampling tool is preferably equipped with some means for exhausting the gases from the ramming chamber subsequent to extension of the tool. Thus, the housing 120 has an exhaust passage 160 providing communication between Achamber 122 and the `exterior of the housing and in which is provided a ball check valve 161. The piston head 133 has an eccentric bore 162 in which is fitted a pin 163 in much the same manner Ias that described in relation to the embodiment of Figs. 1 to 4. The pin 163 has a collar 164 adjacent one end thereof and a spring 165 surrounds the -pin bearing against the collar andb'eing connected to the annular nut 124.

' The operation of the second form of sampling tool is believed to be readily apparent and is briefly summarized at this point. By the operation of -a control switch, not shown, `at a remote control station, the tiring mechanism 153 is activated and an explosion is created in the ramming chamber 122. This thrusts both the inner and outer members 131, 132 of the tool outwardly of housing 120. It will be noted in this regard that the explosive force is effective against both the piston head 133 and 14d inasmuch, as frusto-conical bore 134 permits packing of the exposive charge against the inner piston head 149.

During outward .extension of the tool, the pin 163 is maintained in the exhaust passage 160, as before. Be` cause 'of the telescoping arrangement of the tool, the effective extended length of the tool as a result of providing inner and outer telescoping members, is approximately double that of its length in retracted position.

After the tool has penetrated a formation and a sample has been packed Within the barrel 142 of the inner memberV 132, the springs 139 and 143 bot-h urge their respective members into retracted position. Since the pin 163 lhas been dropped out of plugging relation with the exhaust passage in the limit of the extension stroke, in the same manner as :above described, the retraction of piston heads 133 and 140 force exhaust gases out the passage 11.60.

The sampling tool ofthe second form may be mounted in a housing with other sampling tools of a telescoping nature or with a tool such as that shown in therst form of the invention. In yany event, after a sample has been received in the telescopic tool, the apparatus may be lifted from' the well or bore Ihole and by removing the annular nut 137, access may be had to the inner' member 132 for removal of the sample.

Other modifications may be provided in the telescoping sampling tool such as the screw threaded attachment of the inner cylinder 141 to the inner piston head 140. Further, an exhaust pasage similar to 95 of Figs. 3 and 4 could be provided in that of Fig. 5.

From the foregoing, it will be apparent that several improvements have been shown and. described in the construction of a sampling tool. These improvements facilitate the extraction of sampling tools from penetrated formations i-n a more dependable manner. Further, sampling tools made in accordance with the principles of this invention enable deeper penetration of earth 4formations whereby more complete and accurate analysis of the samples may be made. Although the sampling tools are shown as mounted for movement in substantially right angular relation to the housing, it will be evident that the tools could be mounted for movement along paths having any other desired angular relation to the housing.

Although the invention has been herein shown and described in what is conceived to be the most practical :and preferred embodiments, lit is recognized that departures may be made therefrom within the scope of the invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices and apparatus.

Having described my invention, what I claim as new :and desire to secure by Letters Patent is:

l. A geological sampling apparatus comprising a body member adapted to be lowered into an earth cavity and providing ya ramming chamber therein having a closed end and -an end opening outwardly of the body member, a 11am mounted for reciprocal movement in the chamber, a sampling tool releasably connected to the ram mounted for slidable reciprocation in the chamber between a wholly housed position within the chamber and a position extended from the body, explosive means for thrusting the tool into extended position, means releasably tted in the chamber of the body member limiting extended movement ofthe tool to prevent separation of. the tool from the body when the tool is extendedv by the explosive means, and means automatically thrusting the tool from extended to wholly housed position when the tool reaches its limit of outward extension.

2. In a geological sampling apparatus including an elongated body adapted for elevational positioning in a bore hole and having a plurality of piston chambers trans-V versely disposed in longitudinal spaced relation therein, the piston chamber having closed inner ends and outer ends opening exteriorly of the body, annular members releasably iitted in the outer open ends of the chambers having bores therein slidably receiving the piston means and retaining the piston means in the chambers, piston means individually mounted in the piston chambers for reciprocation between retracted positions withintheir chambers and positions extended outwardly in their chambers, an explosive charge disposed in each of the piston chambers against the piston means therein and the closed ends of the chambers for thrusting the piston means into extended position, means connected to each of the piston means for automatcially returning the piston means into retracted positions in their chambers upon completion of such outward extension, sample-receiving coring tools releasably mounted on the piston means slidably mounted in the bores of the annular members extendible out of the body for receiving earth samples during outward ex- 8 tensionof; the piston means associated therewith, and selective control means for tiring the explosive charges.

3. A geological sampling apparatus comprising a body member providing a chamber therein, a sampling tool mounted* in the chamber for reciprocal movement between a retracted position within the chamber and a position extended from the body adapted in the extended position to receive an earth sample, explosive means for thrusting the tool into extended position, the body providinga vent between the exterior of the body and the chamber, means normally closing the venting means, closure means for the vent, means urging the closure means into a position closing the vent and being yieldable incident to a predetermined explosive pressure in the chamber to move into a position opening the vent, means removably plugging the vent, means connected to the tool engaging the plugging means in substantially the fully extended position of the tool to remove it from the vent thereby to condition the vent to be opened by the closure means, and control means for firing the explosive means.

4. A geological sampling apparatus comprising a body member providing a ramming chamber therein, a ram mounted in the chamber for reciprocation between retracted and extended positions, means yieldably urging the ram into retracted position, explosive means in the chamber for thrusting the ram into extended position, a sampling tool releasably connected to the ram adapted for extension and retraction relative to the body in response to extension and retraction of the ram and having a sample receiving end adapted to receive an earth sample upon extension of the tool, the body having a vent therein providing communication between the ramming chamber and the exterior of the body, a valve having a position closing the vent adapted to be moved into a position opening the vent incident to a predetermined pressure in the chamber, means plugging the vent precluding opening thereof by the valve when the ram is in retracted position and during movement of the ram toward extended position, means connected to the plugging means engaged by the ram for removing the plugging means from the vent in substantially the fully extended position of the ram and for maintaining the plugging means so removed during movement of the ram from extended to substantially fully retracted position, and control means for firing the explosive means.

5. A geological sampling apparatus comprising a body providing a chamber therein, a sampling tool mounted in the chamber for reciprocal movement between a retracted position within the chamber 4and a position extended from the body adapted in the extended position to receive an earth sample, explosive means in the chamber for thrusting the tool into extended position when fired, means yieldably urging the tool into retracted position, the body providing a vent passage connecting the chamber to the exterior of the body, a latch normally closing the vent passage, means for releasing the latch from closing relation in the vent passage triggerable in substantially the fully extended position of the sampling tool, means for maintaining the latch in released condition during substantially the full retraction stroke of the sampling tool and for returning the latch to vent passage closing condition when the sampling tool has returned to substantially fully retracted position, and control means for firing the explosive means.

6. A geological sampling apparatus comprising a body member providing a ramming chamber therein having an open end and a closed end, a ram mounted in the chamber for reciprocation between retracted and extended positions therein and providing a piston head having an eccentric bore therethrough, means yieldably urging the ram into retracted position, explosive means in the chamber between the closed end thereof and the piston head for thrusting the ram into extended position, a sampling tool threadably connected to the ram adapted for exten` sion andY retraction relative to the body in response to asoasosi extension and retractionV of the ram and having a sample receiving end adapted to receive an earth sample upon extension of the tool, the bodyproviding a gas exhaust passage extending through the closed end of the chamber and connecting the chamber with the exterior of the body, an elongated pin slidably loosely received in the eccentric bore, means yieldably urging the pin into aligned plugging relation in the exhaust passage when the ram is in retracted position and during substantially the full extension stroke of the ram, means on the pin engageable with the piston head in substantially the fully extended position of the ram for removing and misaligning the pin from the passage whereby the loose reception of the pin in the eccentric bore permits maintenance of such misalignment during substantially the full retraction stroke of the ram, andcontrol means for iring the explosive means.

7. A geological sampling apparatus comprising a body member providing a ramming chamber therein having an open end and a closed end, an annular nut threadably fitted in the open end4 of the chamber providing a central bore therethrough, a ram mounted in the chamber for reciprocation between retracted and extended positions therein and providing a piston head having an eccentric bore therethrough, a spring positioned in the chamber between the annular nut and the piston head yieldably urging the ram into retracted position, explosive means in the chamber between the closed end thereof and the piston head for thrusting the ram into extended position, a sampling tool threadably connected to the ram slidably received in the central bore of the nut and adapted for extension and retraction relative to the body in response to extension and retraction of the raml and having a sample receiving core adapted to receive an earth sample upon extension of the tool, the body providing a gas exhaust passage extending through the closed end of the chamber and connecting the chamber with the exterior of the body, an elongated pin slidably and loosely received in the eccentric bore and extended between the annular nut and the closed end of the chamber, a collar rigidly attached to the pin on the end thereof adjacent to the annular nut, the pin normally being fitted in closing relation in the exhaust passagewhen the ram is in retracted position and during substantially the full extension stroke of the ram, a spring bearing against the collar yieldably urging the pin into said closing relation, the collar being positioned on the pin for abutment with the piston head in substantially the fully extended position of the ram thereby releasing thepin `from said closing relation, said last mentioned spring and the loose fit of the pin in said eccentric bore being adapted to maintain the pin out of closing relation with the pasage during substantially the full retraction stroke of the ram, a further exhaust port providing communication between the chamber and the exterior of the body only in the fully extended position of the ram, and controlV means for tiring the explosive charge.

8. A telescoping sampling tool having outer and inner telescoping members mounted `for relative reciprocal movement with the inner member retracted and extended relative to the outer member, the outer member having an outer piston head providing a concentric bore and having a cylindrical portion extended Vfrom the piston head, the outer member further having an inner ramming chamber withvan outer open end and an inner end cornmunicating with the concentric bore, an inner annular nut threadably fitted in the outer end of the inner chamber providing a central bore therethrough, the inner member having an inner piston head abutting against the concentric bore in the outer piston head in closing relation thereto, the inner member further having an inner cylindrical portion extended from the inner piston head for slidable movement through the bore of the inner annular nut and providing a core-receiving barrel, and a spring in theinner chamber around the, inner cylindrical portion between the inner annular nut and the inner piston head for yieldably urging the inner memberV into i'etr'a'c'tedi'po'sition within the outer member.

9. A geological sampling apparatus comprising a body member providing a chamber therein, a telescoping sampling tool having inner and outer telescoping members mounted in the chamber for reciprocal movement between a retracted position within the chamber and a position extended from the body, the inner member having a core-receiving barrel adapted in the extended position in the tool to receive an earth sample, means yieldably urging the outer member into, retracted position within the chamber, means yieldably urging the inner member into retracted position within the outer member, explosive means in the chamber for thrusting the tool into extended position with the inner member extended from the outer member and the outer member extended from the body, the body providing vent means between the exterior of the body and the chamber, means normally closing the ventmeans when the sampling tool is in retracted position and during substantially the full extension stroke thereof, means for conditioning the vent means for opening triggerable in substantially the fully extended position of the sampling tool and operable to maintain the vent means so conditioned during substantially the full travel of the sampling tool from its extended position to its retracted position, and control means for ring the explosive means.

l0. A geological sampling apparatus comprising a body member providing an outer ramming chamber therein having a closed end and an open end, an outer annular nut threadably tted in the open end of the outer chamber providing a central bore therethrough, a telescoping sampling tool having outer and inner telescoping members mounted in the chamber for reciprocal movement between a retracted position within the chamber and a position extended from the body, the outer` member having an outer piston head providing a concentric bore, a spring in the outer chamber between the annular nut and the piston head, the outer member providing a cylindrical portion extended from the piston head for slidable movement through the bore of the annular nut and having an innerV ramming chamber with an outer open end opening exteriorly of the body member and an inner end comr municating with the concentric bore, an inner annular nut threadably fitted in the outer end of the inner charnber and providing a central bore therethrough, the inner member having an inner piston head abutting against the concentric vbore in the outer piston head in closing relation thereto, the inner member further having an inner cylindrical'portion extended from the inner piston head for slidable movement through the bore of the inner annular nut and providing a core-receiving barrel opening outwardly of the body, a spring in the inner chamber around the inner cylindrical portion between the inner annular nut and the inner piston head for yieldably urging the inner member into retracted position within the outer member, explosive means in the outer chamber between the closedend thereof and the outer piston head and within the concentric bore of the outer piston head for thrusting the inner and outer members outwardly into their extended position, and control means for tiring the explosive means.

vll. A geological sampling apparatus comprising an elongated body member adapted for elevational positioning in a borehole and having an elongated piston chamber transversely disposed therein, the piston chamber having an open outer end and an inner end providing an opening therein, anannular member releasably tted in the open outer end of the chamber providing a central bore, a closure member removably tted in the opening in the inner end of the chamber, a sampling tool having inner and outer open ends mounted in the chamber slidably fitted inthe bore of the annular member for slid-able extension outwardly of the body member, a piston releasably mounted inthe inner open end of the sampling tool andslidably received in the chamber for reciprocal movement therein, and explosive means in the chamber between the inner end thereof and the piston adapted upon firing to thrust the piston outwardly in the chamber to extend the sampling tool outwardly of the body member.

12. A geological sampling apparatus comprising a body member providing a chamber therein, a sampling tool mounted in the chamber for reciprocal movement between a retracted position within the chamber and a position extended from the body adapted in the extended position to receive an earth sample, explosive means in the chamber adapted upon firing to thrust the tool from the body member, means yieldably uring the tool into the chamber, the body member providing a vent passage interconnecting the chamber and the exterior of the body member to permit exhaust of gas from the chamber incident to firing of the explosive means, plugging means in the chamber movable between a closing position in the vent passage and a position removed from the passage, means connected to the tool engageable with the plugging means to remove it from the passage when the tool is in substantially fully extended position and to replace it in the passage when the tool is in substantially fully retracted position, and means for firing the explosive means.

13. A geological sampling apparatus comprising a body member providing a ramming chamber therein having au open end and a closed end, a ram mounted in the chamber for reciprocation between retracted and extended position therein and providing a bore therethrough, means yieldably urging the ram into retracted position, explosive means in the chamber between the closed end thereof and the ram for thrusting the ram into extended position, a sampling tool connected to the ram adapted for extension and retraction relative to the body in response to extension and retraction of the ram and having a sample receiving end adapted to receive an earth sample upon extension of the tool, the body providing a gas exhaust passage extended through the closed end of the chamber and connecting the chamber with the exterior of the body, an elongated pin slidably loosely received in the bore, means yieldably urging the pin into aligned plugging relation in the exhaust passage when the ram is in retracted position and during substantially the full extension stroke of the ram, means on the pin engageable with the ram in substantially the fully extended position of the ram for removing the pin from the passage, and means for tiring the explosive means.

14. A geologic-al sampling apparatus comprising a body providing a chamber therein having a closed rearward end and an open forward end, the body having a rear vent passage extended between the chamber and the exterior of the body and a forward` vent passage extended between the forward end of the chamber and the exterior of the body, a sampling tool, ram means connected to the tool slidably reciprocally mounted in the chamber for movement between predetermined forward and rearward positions therein located rearwardly of the forward vent passage in said rearward position and forwardly of the forward passage in said forward position, valve means closing the vent passages operable incident to predetermined pressure in the chamber to vent the ch-amber, explosive means in the chamber for moving the ram forwardly, and means yieldably urging the ram into rearward position.

l5. A geological sampling apparatus comprising a body providing a chamber therein having a closed inner end and an open outer end, a ram mounted in the chamber for reciprocal movement between the inner and outer ends and dividing the chamber into substantially air-tight sections forwardly and rearwardly thereof, explosive means in the inner end of the chamber rearwardly of the ram for thrusting the ram outwardly incident to firing thereof, means yieldably urging the ram into inner position, the body providing a first. vent passage extended therethrough evening' into the chamber and exterieur of the bgdy adapted to vent; the harnber. forwardly of; the ram during movement thereof into outer position, a valve yieldably closing the fir-stvent passage openable incident to predeter-mined pressure in the chamber during said movement of thek ram to outer position and remaining closed during movement of the ram to inner position to create a low pressure in the section of the chamber forwardly of the rarn relative to the section rearwardly of the ram, the body having a second vent passage in the inner end of the chamber providing communication between the cham- 'ber and the exterior of the body, valve means yieldably closing the second vent passage openable incident to predetermined pressure in the chamber rearwardly of the ram during movement thereof into inner position, and a sarnpling tool connected to the ram extendible out of the body during movement of the ram to outer position.

16. A sampling apparatus comprising a body member providing an outer chamber therein having a closed inner end and an open outer end, inner and outer telescoping members mounted in the chamber for slidable reciprocal movement between a retracted position within the chamber and an extended position out of the open end of the chamber, the outer member having an outer piston head and an outer elongated tubular member extended from the headproviding an inner chamber, the inner member having an inner piston head abutting against the outer piston head within said inner chamber and having an in ner tubular member extended from the inner piston head within said inner chamber and providing an internal corereceiving barrel, the outer chamber providing a tiring compartment having a rear wall defined by the closed inner end of the outer chamber and a forward wall defined by the inner and outer piston heads, explosive means in said firing compartment engageable with both of said piston heads, means for tiring the explosive means, and means in the inner chamber of the outer member engageable with the inner member preventing separation of said members during telescopic extension thereof.

1,7. A telescopic sampling tool having inner and outer telescoping members mounted for relative reciprocal movement with the inner member retracted and extended relative to the outer member, the outer member having an outer plate-shaped piston head providing an opening extended therethrough and an elongated outer sleeve ex.

tended from the piston headl circumscribing an internal ramming chamber havingy an outer open end, the inner member having an inner piston head diametrically extended transversely of the internal chamber so as to occupy substantially the entire cross-sectional area of the internal chamber, the outer piston head being extended transversely inwardly' of the outer sleeve, the inner piston head abutting the outer head and marginally overlapping the opening in the outer piston head so as to close such opening when the inner member is retracted relative to the outer member, the inner member also having an inner elongated sleeve extended from the inner piston head within the outer sleeve and circumscribing an internal core-receiving barrel having an outer open end and a closed inner end dened by the inner piston head, means for extending and retracting the inner and outer members and means mounted in the outer end of the outer sleeve engageable with the inner member preventing separation of the inner and outer members during extension thereof.

1S. A sampling apparatus comprising a body member providing an outer chamber therein having a closed inner end and an outer open end; inner and outer telescoping members mounted in the chamber for slidable telescopicv movement between a retracted position within the chamber and an extended position out of the open end of the chamber, the outer member providing an outer discoidallyshaped piston head extended transversely of the outer chamber and having an opening extended therethrough, the area of the opening being less than the? area of the remainder of theoute piston head, the outer member having an outer sleeve extended from the outer piston head providing an inner chamber communicating with the opening, the inner member having an inner discoidallyshaped piston head extended diametrically across the inner chamber so as to occupy substantially the entire cross-sectional area of the inner chamber. the inner piston head abutting the outer piston head in closing marginally overlapping relation to the opening in the outer piston head when the telescoping members are in retracted position, the inner member further having an inner sleeve extended from the inner piston head providing an internal core-receiving barrel; means in the outer chamber of the body between the closed end of the chamber and the outer piston head, extended through the opening in the outer piston head, in contact with the inner and outer piston heads and adapted to thrust the telescoping mem- 14 bers outwardly of the body member into their extended positions; means for extending and retracting the inner and outer members and means in the inner chamber of the outer member engageable with the inner member for preventing separation of said members in the extended position thereof.

References Cited in the le of this patent UNITED STATES PATENTS 2,067,693 Carey Ian. 12, 1937 2,545,306 Pollard Mar. 13, 1951 2,599,040 Bannister June 3, 1952 2,612,346 Nelson Sept. 30, 1952 2,678,804 Lebourg May 18, 1954 

